Fuel injection pump



March 23, 1954 W FRlEDLANDER 2,672,816

FUEL INJECTION PUMP Filed June 16, 1950 2 Sheets-Sheet 1 March 23, 1954 Filed June 16, 1950 W. FRIEDLANDER FUEL INJECTION' PUMP 2 Sheets-Sheet 2 Patented Mar. 23, 195:4

FUEL INJECTION PUMP William Friedlander, Westminster, London, England, assignor to Mono-Cam Limited, London, England, a company of Great Britain Application June 16, 1950, Serial No. 168,508

Claims priority, application Great Brita June 17, 1949 i 7 Claims. 1

This invention relates to fuel injection pumps for internal combustion engines, particularly though not exclusively, compression-ignition engines. it is concerned with improvements in pumps of the kind (hereinafter referred to as the kind specied) in which the effective length of the delivery strokes of the respective pistons is similarly controlled simultaneously for all the pump cylinders, by actuation of a common regulating member which adjusts, for each cylinder, the position of an element which determines at What point in the delivery stroke fuel will be spilled from the cylinder into a chamber or passage in communication with the inlet side of the pump, the fuel tank or a like low-pressure region, the common regulating member being a plate or disc and the elements adjusted thereby being sleeves fitted over the pump pistons or plungers to control the outlet ends of spill passages which run through the pistons or plungers from the operative end faces thereof to the cylindrical surfaces thereof.

Various proposals have heretofore been made for controlling the delivery of pumps of the kind specified automatically in accordance with the speed and loading of the engines supplied thereby, so that a certain speed governing action will be secured which will prevent the engine speed from varying to any substantial extent from the value thereof corresponding to the setting for the time being of the manual or other control normally employed for actuating the common regulating member.

The object of the present invention is to provide an improved automatic delivery-controlling device for a pump of the kind specified which shall be sensitive, efcient and of relatively simple construction.

According to the invention, in a pump of the kind specified, the common regulating member is connected to a rigid or immovable part of the pump housing by means of a pressure-responsive element entirely disposed Within the housing, and means is provided for exposing the said element to the variable pressure in one of the manifolds of the engine being supplied by the pump in such a sense as to cause the pressure-responsive element to move the regulating member in the direction for reducing the delivery of the pump as the engine speed increases above the value for which it is set by the normal control means.

It is preferred to utilise the reduced pressure in the intake manifold of the engine but the pressure in the exhaust manifold may instead be utilised in the case of supercharged engines.

In order that the nature of the invention may be clearly understood, an example of the Way in which it may be carried into effect will now be described in greater detail with reference to the accompanying drawings.

In this example, the pump chosen for illustrative purposes is constructed substantially in accorclance with the invention forming the subject matter of application Serial No, 687,368, now Patent No. 2,517,483, but the present invention may be applied also to other constructions of pumps of the kind specied above without difficulty.

In the drawings:

Fig. 1A is the upper part of a section taken on the line I-I of Fig. 2,

Fig. 1B is the lower part of the section, and

Fig. 2 is a section taken on the line II--II of Fig. 1A.

The pump, as shown in Fig. 1A, comprises a generally cylindrical housing I having a cam chamber 2 (Fig. 1B) at one end, a spill chamber 3 intermediate its length and a series of delivery connections 4 at its other end which are each connected to the fuel injection device of the respective engine cylinder. At this end of the housing there are the appropriate pump cylinders 5 disposed around and parallel with the axis of the housing and each communicating through a delivery valve 6 with the corresponding delivery connection 4. The cylinders 5 and the respective pistons or plungers 'I are all identical and only one set of these parts need be described here. The cylinder wall is formed with radial bores 8 near its outer end and is surrounded at this location by an annular fuel supply passage 9. This is in permanent communication with a central annular chamber I0 (supplied from an inlet Illa through a bore lob) formed by a recess in the cylindrical wall of the enlarged inner end II of an axial bore I2 in the housing I provided to admit the passage of a stem I3 attached to a common regulating member I4 located in the spill chamber 3. The regulating member Ill is of disc form with a thickened edge I5 on to which is clamped a ring I serving to position controlling sleeves Il which are a close sliding t on the pistons l Working in the cylinders,y 5. Each piston 'I is a close sliding fit in its cylinder 5 which projects, With play, part-way into an aperture I8 in the thickened edge I5 of the regulating member, the corresponding controlling sleeve il being mounted on the latter in such a manner that it may move laterally (e. g. radially or circumferentially of the member) Without being capable of any appreciable motion relative to the member in the axial direction.

The piston 'I continues beyond the sleeve I'I, through an oversize hole I9 in a partition member ZIJZfseCuredtransversely of L.the y:spill chamber 3, to be surrounded" by a compression `s1`3rir1g2 bearing at its ends upon the partition member 20 and upon a collar 22 secured on the endf the piston, respectively. The end ofthe piston 'I bears upon one end of a reciprocable push`ro`d 23 the other end of Whichplseeilig.13)carries a roller 24 co-operatinglwith -aifacecam .25;.10- tatable Within the cam chamberE-by means of a shaft 26 extending axiallythroughthe end of the housing I to be driven from the"e'ng'irie crank-shaft at an appropriatespe'ed.

Centrally of the partition member 20 (seeeFig. 1A) is formed an axially extending cylindrical wall 21 surrounding aliner 28 Within which'slides a spigot part 2,9 secured on the regulating inembeiff'ld." f'glvxiali'adju'stmeto'f thismember varies tlie'y position of 'the controlling sleeves-ill rela- .tivetojth length of vthe pistonsl I which 4are Y Vv'foiiried"v/iai axial bores so reading from their operative end faces to radial 'bores'l vthe opening 'vofvwliich occurs 'as they move out of thel controlling sleeves'fjll 4j'iuringthe delivery strokes fofth'e respectiveypistons'. 'Ifh'epiimp Ythus 'far;describ ed ,operatesV in ex- .actlyfthe K,same i manner as that described in "application Serial 'No."j68'768 rotation of the face"arrfZcausingreciprocation ofthe pistons Irandgtheonseguent deliverylper vvoi'kingy'stroke, ofa quantity Aof fueldeterinine'd by the @pacing for themtime being of the contr'ollng "sleeves Il smarte larmes; -`"Wh"i1'e'thepumpis operating, a certain `proportion `of p the fuel initially drawn into f. each yiinqerfelis'spiiied into the chambers containthe rfe'gulatfin'g Y i'r'ember Ill; :the "proportion iiiedv iricreaeiiigasiiie quanti/wier iuei A to `thefengine per stroke'bf "e'a'ch piston es.

"jtenevvsf 32' having'fitsjefifds attached* inaia-eidytight mannertthe 'izi'a'rtitinmember'y 2a and connection is' made,- at '33, fromftheen'gine intake #manifold-to a -radial-boreiirl formed in.. the partitioni member4 .21) this borev opening through .the liner v28.V to the space;.;35-..bounded by ithe latter ifwithinethe cylindrical. wallg'l. YThe spigotpor- '.tioni 2,9on ..theregulatingrAmember 1:4 sftself formed .with an. axial` bore. .3.6 .fr0mi its .'.freeenw .which ,@Ommimicetes .with substantially. radial ores-tl ,-iO. med :in the .SDgQt Portion. @13d 1,101- amal1y;hari1gtheir flmQuthS .JuSt .covered-by 'the ee `edge of theliner .12.8. Thespigot. portion 23 .1s fhowever v SligfhlilY reduced in 'fdiameterf at" this ilocation (as 1.shown 'at s'o'vthat'jthe pressure Avariations f in thefen'gine manifld, can `act jupon the' interior A of"l the' pressureV responsive bellows ...32. Theareneemilti 1S. ,Silhthat fan' Yiriifefis@ lintbeslltiii in the menifeldlwill @fillers/ .the `bellini/s 32 to a smaller axial lengthan'd-thus v`draw 'the vregulating membery I 4 towardsthe pair'- l0 if necessary, will allow the bellows to expand again;sothattheregulating member I4 will then movefin thed ection for increasing the supply Y`of4 ffuei jioitheA engine.

vKlnorlerrftlfatNthe regulating member I4 may normally" be adjusted by hand or other means,

kp,articjulaulyrior the purposes of `stopping the engine and determining the maximum fuel de- Hliyverv. the stem I3 thereof is extended by a 'screwed-on rod 39 which carries at its free end a head `4I) adapted `to be ycontacted by onen arm SillV oiga two-'armed actuating lever?ll'l'gfpivqted yat 431011 a` tubular exten's'i'oriffll se'cured o'nthe pump/housing I -The' rodi' 39` Ysealedli1- -the housing by means ofi afflexible bellows lf'llS-contheinner ene ofwhich iscostituted by ash'dule911 .The eener-tsl also acts: as air` abutmenefor one fend of alcompressionvsprngaithe A.other end j of which bears against` ash'oulderii I nifthe passageith'rougli 'th extension; M. ifhis. yspring isr 'provided -t limit the movement of .the Acontrol member towardsminimum :deliveryundersrthe influencef scti'onin order. towreduceerratic variations of idling speed. It.willHbe-senithat the bellows?4:25l which respondsato the `pressure A y'variation lin-f the engine manifold i may-nevertheatr any setting ofi-theactatingiiever-.Aum.

' The pressurel of Y the .Springhill acting. lonethe regulating x'nernber "I 4 mafy` .bem varied .toi` suit requirements by interposing spacing collars or fand the "screwe'deon ,rod 355i wlii'cli .'-forinsetheextension thereof.

The required engine speed is selected by-vary ling ithe ffree orifice; of "the engine i manifold`r with ,y l u i5-ftheein;effe:pdttefiy'valvelfiiiaeeidaiieewith v"to ',the regulating member M, respectively. A i' Il() iregulatiiig membejthe pressure-responsivebel- 1. A f l'injection pump-comprising ahousing,

c Vofpum'pieyiiiiders ieated'witiiintiie iieiiiggitith tneiiorie; endsadjacent ie eier-emile nouscylinders and said cam, an element slidable on each plunger to determine the point in the stroke of the plunger at which the spill passage therein will be placed in communication with the spill chamber, a regulating member displaceably mounted within the spill chamber and operatively connected to each of the slidable elements, an abutment xedly mounted within the spill chamber, a iiexible bellows disposed within the chamber and operatively connected at one end to the regulating member and at the other end to the abutment, an inlet connection on the exterior of the housing and a passage leading from the inlet connection to the interior of the bellows,

2. A fuel injection pump comprising a housing, a plurality of fuel delivery conduits, a plurality of pump cylinders located within the housing with their one ends adjacent to one end of the housing, a valve-controlled connection from said end of each cylinder to a respective delivery conduit, a pump plunger reciprocable in each cylinder, a common cam for reciprocating the plungers, a spill passage in each plunger having an outlet end, a spill chamber located in the housing entirely between said ends of the cylinders and said cam such that the outlet ends of the spill passages will Ibe moved through the chamber by the reciprocation of the plungers, an element slidable on each plunger to determine for what proportion of each stroke of the respective plunger the outlet end of the spill passage therein will be in communication with the spill chamber, a common regulating member displaceably mounted within the spill chamber, operative connections between the said member and the elements slidable on the plungers for causing these elements to move in unison with the regulating member, movement of the latter in one direction therefore resulting in a reduction in the output of the pump and movement in the 4 opposite direction resulting in an increase in said output, an abutment xedly mounted within the spill chamber at a distance from that side of the regulating member which leads when the member is moved in the said one direction, a flexible bellows entirely located within the spill chamber and operatively connected at one end to the regulating member and at the other end to the abutment, an inlet connection on the exterior of the pump housing, and a passage leading from the inlet connection to the interior of the bellows.

3. A fuel injection pump comprising a housing, a plurality of fuel delivery conduits, a plurality of pump cylinders located within the housing with their one ends adjacent to one end of the housing, a valve-controlled connection from said end of each cylinder to a respective delivery conduit, a pump plunger reciprocable within each cylinder, cam means for reciprocating the plungers, a spill passage in each plunger, a spill chamber located entirely between said ends of the cylinders and said cam means, an element slidable on each plunger to determine the point in the stroke of the plunger at which the spill passage therein will be placed in communication with the spill chamber, a regulating member displaceably mounted within the spill chamber and operatively connected to each of the slidable elements, a partition member xedly mounted within and transversely of the spill chamber, a flexible bellows disposed within the chamber and directly connected at one end to the regulating member and at the other end to the partition member, an inlet connection on the exterior of the housing and a passage leading from the inlet connection to the interior of the bellows.

4. A fuel injection pump comprising a housing, a plurality of fuel delivery conduits, a plurality of pump cylinders located within the housing with their one ends adjacent to one end of the housing, a valve-controlled connection from said end of each cylinder to a respective delivery conduit, a pump plunger reciprocable within each cylinder, cam means for reciprocating the plungers, a spill passage in each plunger, a spill chamber located entirely between said ends of the cylinders and said cam means, an element slidable on each plunger to determine the point in the stroke of the plunger at which the spill passage therein will be placed in communication with the spill chamber, a regulating member displaceably mounted within the spill chamber and operatively connected to each of the slidable elements, a partition member xedly mounted within and transversely of the spill chamber, a ilexible bellows directly connected at one end to the regulating member and at the other end to the partition member to dene a secondary chamber located entirely within the spill chamber, an inlet connection on the exterior of the housing and a passage leading from the inlet connection to said secondary chamber.

5. A fuel injection pump comprising a housing,

` a plurality of fuel delivery conduits, a plurality of pump cylinders located within the housing with their one ends adjacent to one end of the housing, a valve-controlled connection from said end or each cylinder to a respective delivery conduit, a pump plunger reciprocable within each cylinder, cam means for reciprocating the plungers, a spill passage in each plunger, a spill chamber located entirely between said ends of the cylinders and said cam means, an element slidable on each plunger to determine the point in the stroke of the plunger at which the spill passage therein will be placed in communication with the spill chamber, a regulating member displaceably mounted within the spill chamber and operatively connected to each of the slidable elements, a partition member fixedly mounted within and transversely of the spill chamber, a flexible bellows directly connected at one end to the regulating member and at the other' end to the partition member to denne a secondary chamber located entirely within the spill chamber, an inlet connection on the exterior of the housing and a radial bore through said partition member communicating at one end with said inlet connection and at the other end with said secondary chamber.

6. A fuel injection pump comprising a housing, a plurality of fuel delivery connections on the exterior of the housing, a plurality of pump cylinders located within the housing with their one ends adjacent to one end of the housing, a valve connecting said end of each cylinder to its respective delivery connection, a pump plunger reciprocable within each cylinder, a cam for reciprocating the plungers, a spill passage in each plunger, a spill chamber located entirely between said ends of the cylinders and said cam, an element slidable on each plunger to determine the point in the stroke or the plunger at which the spill passage therein will be placed in communication with the spill chamber, a regulating member displaceably mounted within said spill l chamber and operatively connected to each of pla eain Communication with the' Aspin chamber y ahd'a" common" regulating member displaceable simultaneously; h 1 ,p'afrt nxecuy f nrouhtedlv within f extending' 'from 'the exterior "of 'the'pump housing 15 

